Fix(mysql): generate JSON_OBJECT properly (#2139)

* Fix(mysql): generate JSON_OBJECT properly

* Move common function to dialect and use TRANSFORM

sqlglot/dialects/bigquery.py

@@ -12,6 +12,7 @@
     datestrtodate_sql,
     format_time_lambda,
     inline_array_sql,
+    json_keyvalue_comma_sql,
     max_or_greatest,
     min_or_least,
     no_ilike_sql,
@@ -417,6 +418,7 @@ class Generator(generator.Generator):
             exp.ILike: no_ilike_sql,
             exp.IntDiv: rename_func("DIV"),
             exp.JSONFormat: rename_func("TO_JSON_STRING"),
+            exp.JSONKeyValue: json_keyvalue_comma_sql,
             exp.Max: max_or_greatest,
             exp.MD5: lambda self, e: self.func("TO_HEX", self.func("MD5", e.this)),
             exp.MD5Digest: rename_func("MD5"),
@@ -651,6 +653,3 @@ def version_sql(self, expression: exp.Version) -> str:
                 expression = expression.copy()
                 expression.set("this", "SYSTEM_TIME")
             return super().version_sql(expression)
-
-        def jsonkeyvalue_sql(self, expression: exp.JSONKeyValue) -> str:
-            return f"{self.sql(expression, 'this')}, {self.sql(expression, 'expression')}"

sqlglot/dialects/dialect.py

@@ -725,3 +725,8 @@ def parse_timestamp_trunc(args: t.List) -> exp.TimestampTrunc:
 
 def any_value_to_max_sql(self: Generator, expression: exp.AnyValue) -> str:
     return self.func("MAX", expression.this)
+
+
+# Used to generate JSON_OBJECT with a comma in BigQuery and MySQL instead of colon
+def json_keyvalue_comma_sql(self, expression: exp.JSONKeyValue) -> str:
+    return f"{self.sql(expression, 'this')}, {self.sql(expression, 'expression')}"

sqlglot/dialects/mysql.py

@@ -8,6 +8,7 @@
     arrow_json_extract_scalar_sql,
     datestrtodate_sql,
     format_time_lambda,
+    json_keyvalue_comma_sql,
     locate_to_strposition,
     max_or_greatest,
     min_or_least,
@@ -531,6 +532,7 @@ class Generator(generator.Generator):
             exp.GroupConcat: lambda self, e: f"""GROUP_CONCAT({self.sql(e, "this")} SEPARATOR {self.sql(e, "separator") or "','"})""",
             exp.ILike: no_ilike_sql,
             exp.JSONExtractScalar: arrow_json_extract_scalar_sql,
+            exp.JSONKeyValue: json_keyvalue_comma_sql,
             exp.Max: max_or_greatest,
             exp.Min: min_or_least,
             exp.NullSafeEQ: lambda self, e: self.binary(e, "<=>"),

tests/dialects/test_mysql.py

@@ -829,3 +829,6 @@ def test_set_variable(self):
 
         cmd = self.parse_one("SET x = 1, y = 2")
         self.assertEqual(len(cmd.expressions), 2)
+
+    def test_json_object(self):
+        self.validate_identity("SELECT JSON_OBJECT('id', 87, 'name', 'carrot')")